<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.w3.org/1999/xhtml">
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>

<body>
欢迎 <p th:text="${user.username}" />  登陆系统！！！
</body>
</html>